File photo undated shows a T164 train, running along the Qinghai-Tibet Railway, passes under the foot of the Tanggula Mountain of southwest China's Tibet Autonomous Region. [Xinhua]
File photo taken on Dec. 24, 2004 shows a steam engine train rolls in the Hexigten Banner, north China's Inner Mongolia Autonomous Region. [Xinhua]
File photo undated shows a T164 train, running along the Qinghai-Tibet Railway, passes under the foot of the Tanggula Mountain of southwest China's Tibet Autonomous Region. [Xinhua]
